I have an APP10 UPD15 customer trying to add the Delivery Note number to Customer Order Invoice - his ask:

“I am attempting to add the Delivery Note number as a reference custom field to several screens related to the Customer Order Invoice. The Delivery Note number is pulled by the CustomerOrderInvoiceRep layout, but I can't get to the reference used by the layout to duplicate it in the custom field. Where is the invoice layout pulling the Delivery Note number from?”